Vaisala DM70 - Manual (Page 46)

USER'S GUIDE____________________________________________________________________
3. If you are requested to check the environment settings, press
Yes. Then check the pressure settings. To set the ambient
pressure, see section Pressure Settings on page 36.
4. Check that the pressure units of DM70 and
DMT340/DMT242/DM142 are the same.
If not, and you are checking DMT242/DMT142, change the
DM70 pressure unit to bara by pressing Unit on the
corresponding row. You cannot change the pressure unit for
DMT242/DMT142. Then adjust the values as instructed in
section Pressure Settings on page 36.
When using DM70 to check DMT340, you can change the
pressure unit of DMT340 by pressing Unit on the
corresponding row. It is also possible to change the pressure unit
of DMT340 through the transmitters local display/keypad
interface, for instructions, please refer to the DMT340 User's
Guide. Then adjust the values as instructed in section Pressure
Settings on page 36.
5. When the pressure settings are correct, press Exit. Now the
display shows the dewpoint readings T
d/f
of DM70,
DMT340/DMT242/DMT142, and the difference between the
readings ∆T
d/f.
Roman numerals (I and II) after the quantity
abbreviations indicate from which port the readings are coming.
You can follow the measurement trend from the graphical
display.
6. Wait until the readings are stabilized. It can take up to one hour
in very low dewpoints. If the difference between the dewpoint
readings is less than 3 ˚C, there is no immediate need for
adjustment. However, in applications where optimum accuracy
is essential, it is recommended to send the
DMT340/DMT242/DMT142 transmitter to Vaisala (see section
Vaisala Service Centers on page 78) when the difference is
considered significant.
7. Press the Power On/Off button.
8. Disconnect the connection cable.
Field Calibration Check of DMP248
You can use DM70 to display the readings of DMP248 and to
compare readings of DM70 and DMP248. To make the connection,
you will need the 27159ZZ cable. See section Accessories on page 89.
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